As we all know, in Hundred Scenes of the South of the Yangtze River, the city is surrounded by water and at a loss, but in the real world, prosperous cities from ancient times to today are not short of water. So, besides the water vapor in the air, what water is there in the city?
I. Wells
What is a well?
People in China have been using barrel wells for a long time. Most of them have a diameter of 1 ~ 2 meters and a depth of several meters to 20 ~ 30 meters. During construction, people can directly enter the shaft to dig earthwork. This kind of well is only suitable for exploiting shallow groundwater. As shown in the figure:
This thing on the well that takes water by turning is called "pulley":
Winch originated in the Warring States period and is a kind of winch. It was originally used to extract copper ore from the shaft. This windlass is called a lifting windlass. It is mentioned in the annotation "Shi Shuo Xin Yu Joey" of the Four-body Book Interpretation that because we mistakenly hung the plaque 25 feet (about 60.5 meters today) from the ground, we used the lifting winch. When I got off the bus, my head lit up because my children and grandchildren said,' Don't go back to school'. "
Far from it.
As for the winch used to draw water, it is called the well winch, which can be found in Li Jing's poem Ying Tianchang in the southern Tang Dynasty: "Grass grows on the willow embankment, and the winch breaks the golden well." As we all know, Li Jing is a militaristic and extravagant emperor, so you can see the windlass from his words. First, it may only be found in the palace. Second, there may be too many things, which can be seen everywhere. In Shi Shuo Xin Yu Pai Diao, Huan Xuan, Gu Kaizhi and Yin Zhong recorded their "dangerous words": Huan said, "The spearhead is like a knife." Yin said, "Centenarians climb dead branches." Gu Yue said, "There is a baby lying on the windlass in the well." (Behind it is the famous saying, "A blind man rides a blind horse and comes to a deep pool in the middle of the night." ) There are more extensive records of well pulleys in Agriculture Book in Yuan Dynasty and Tiangong in Song Dynasty in Ming Dynasty. Among them, "Agricultural Book" also describes a kind of compound pulley: each end of the rope wound on the shaft is tied with a container. "The device that rotates forward and backward is empty, and the redundant one is at the same level, which works quickly." This saves the transportation time of empty containers; At the same time, the weight of empty containers also plays a certain balance role.
So the question is, when did the well appear? We need to be clear:
China is the first country to drill wells in the world.
In one of China's earliest poems, Song of Digging the Earth, it is mentioned that "work at sunrise and rest at sunset". Dig a well to drink. Farming, eating. What is Dili to me? " Among them, the phrase "digging wells to drink water" shows that we have already had the knowledge of digging wells in ancient times; "General Code": "In the past, the Yellow Emperor began to put wells through the soil to plug the end, and built acres to prevent famine, so that eight houses were wells, and four wells were divided into eight houses, and the wells were dug in the middle." There is also a saying that there were wells in the period of the Yellow Emperor. However, in the book Archaeology of Neolithic Age in China, it is recorded that water wells were found in Dinggong (Nail Palace) site and Xiwu Temple site of Longshan cultural site in Shandong province. To sum up, the well is indeed the earliest invention of China.
What is the use of a well?
Generally, we think of taking domestic water (mainly for drinking), that is, the wells we see in the city are generally used for this purpose. There is such a picture in "Hundred Scenery of Jiangnan":
It means that it is also well water, and the quality is different.
In the Ming Dynasty, Li Shizhen wrote in the Compendium of Materia Medica Seisensui of the Ministry of Water: "Whoever has well water comes from far away." . "That is to say, the quality of mountain spring water is higher than that of well water seeping from nearby rivers and lakes, and the water in urban sewage ditches and sewers is even more inedible. But there is so much water, and how to ensure and improve the water quality has become the main problem in the application of well water.
In ancient times, the water quality of well water was mainly guaranteed from two aspects:
1. Shell, stone, bamboo charcoal and other filtering devices. They are all placed at the bottom of the well, so that the water is filtered by these filtering devices in the first step before being pumped out of the well, which is actually the predecessor of modern water purifiers;
2. Use water skirts, manhole covers and other facilities to protect well water from insects or pollutants;
3. Wash wells regularly to remove dirt and deposits;
4. Putting Chinese herbal medicines into well water;
Besides drinking, well irrigation is the most commonly used well water;
Well irrigation is mainly distributed in northern arid areas, such as Hebei, Shaanxi, Shanxi, Shandong, Henan and other provinces. Well irrigation first appeared in Shang and Zhou dynasties, which is known as well-known well-field system. Why did the Jingtian system get its name? It is not only because the field division under this system is like a well, but also because each group of well-shaped fields has a well for well irrigation and drinking water, which is why the ancient word "well" is often written in the shape of a well. The peak of well irrigation was probably in the Ming and Qing dynasties, which may be related to the relatively dense population and developed farming economy at that time. At the same time, water conservancy books and hydrogeology (referring to open caissons) related to well irrigation, represented by Xu Guangqi's Complete Collection of Agricultural Policies, have also appeared.
Well water can be used not only for drinking and irrigation, but also for medicine-Ejiao, brewing and drinking, so I won't go into details one by one.
So are there any eggs related to wells?
Yes
The foot of my bed is shining with such bright light. Is it frosty already? ? The "bed" here is different from the bed we usually say. In Ci Hai, it refers to:
Inoue fence
The water in the city (above) is over. I wanted to write about sinking, but later I found myself a liberal arts student, not an engineering student. As for the myths related to wells, I attach them here and will not repeat them one by one.
1. Lock Longjing No.2 in Beixinqiao. "Spring God" snail girl knows kindness (later evolved into conch girl) 3. Liu Yilong Palace saved the girl.